Absorbent articles such as diapers, training pants, incontinence products, feminine hygiene products as well as health care related products such as bandages and other wound dressings have a common goal of rapidly absorbing discharged body fluids such as blood, menses, urine and bowel movements. Typically such products will have a body contacting side and surface which is near or in contact with the wearer's skin, some type of absorbent core and a back sheet that will prevent the retained fluids from exiting the product and possibly soiling the surrounding areas including the wearer's clothes.
Thus, it is desirable for such products to rapidly take in fluids, pass them to subjacent layers in the product and provide air circulation adjacent the wearer's skin to promote skin wellness. Air circulation allows drying of the skin to prevent skin irritation such as diaper rash in the case of diapers, training pants and incontinence devices. Air circulation also provides increased comfort by allowing the body contacting material, often referred to as a top sheet or liner, to dry out. In addition, comfort and dryness can be further enhanced by minimizing the amount of the liner material that is in direct contact with the skin. This also facilitates a reduction in what is called “rewet” which is the backflow of fluid from the absorbent core onto the liner. As these are desirable attributes for such products, a number of materials and products have attempted to provide these results. For example, U.S. Pat. Nos. 5,667,619, 5,667,625 and 5,817,394 to Alikhan et al. disclose a fibrous laminate material as well as products incorporating the laminate and an apparatus for making the laminate material. Two fibrous layers are bonded together in a spaced apart bonding pattern comprising compacted bonding regions with lesser bonded fiber spans in between with substantially circular apertures formed in the bonded areas.
U.S. Pat. No. 7,386,924 to Muth et al. discloses a perforation device for perforating prebonded nonwovens having embossing points. Needles of a needle roller engage the prebonded nonwoven and perforate it and the perforated nonwoven undergoes further processing. U.S. Pat. No. 6,849,319 to Cree et al, discloses apertured nonwoven composites for use with absorbent articles. The composite top sheet includes a resilient three dimensional apertured formed film, a nonwoven web with small scale apertures and large scale apertures. The formed film is between the absorbent core and the body facing side. The formed film has a male side and a female side opposite the male side, and small scale apertures with a mesh count. The nonwoven web of fibers is between the formed film and the body facing side of the absorbent article. The large scale apertures extend through the nonwoven web and the formed film. The large scale apertures have a mesh count which is less than the mesh count of the small scale apertures.
U.S. Pat. No. 5,997,986 to Turi et al. discloses apertured plastic films which comprise a stretchable thermoplastic polymeric material having a plurality of microholes defined by a network of fiber-like elements. The films are produced by directing fluids, especially water, against the upper surface of a starting film in the form of columnar streams in a contact zone, while the film is supported on a backing element. EP 0 235 309 to Suzuki et al, discloses a facing for absorptive articles and the associated process for making it. The facing comprises a non-woven fabric having two layers of different fiber compositions with a first layer defining a surface to be in contact with the wearer's skin and having a pattern of apertures and a second layer defining a rear side with respect to the surface and having no apertures. In the process, the first layer is formed by subjecting a fibrous web to a high velocity water jet treatment on a support carrying thereon aperture formation elements, forming the second layer by subjecting a fibrous web to the aforementioned treatment or a heat fusion treatment, and simultaneously combining the first layer integrally with the second layer with either of the aforementioned treatments.
U.S. Pat. No. 5,895,380 to Turi et al. discloses absorbent products having a permeable cover made of a microperforated fibrillated thermoplastic film. The cover is characterized by having non perforate regions and perforate regions, the perforate regions having a plurality of microholes defined by a network of fiberlike elements, the perforate regions being, at least in part, at elevations that are higher than the nonperforate regions. The perforate regions are caused to be at higher elevations by methods such as tensioning the cover or by partly adhering the cover to the absorbent body of the product or by combinations thereof. Additional improvement of fluid acceptance and distribution properties are said to be obtained by corona discharge treatment of one side of the film before microperforating and by treating the microperforated film with surfactant.
European Patent No. 0 705 932 to James et al. discloses nonwoven fabrics having a fibrous background portion in one plane thereof and raised fibrous portions in another plane thereof. There may be two types of raised portions. In one type, the basis weight of the raised portion is substantially the same as the basis weight of the background portion. In another type of raised portion, the basis weight is greater than the basis weight of the background portion. The raised portions are joined to the background portion by a fibrous transition region. U.S. Pat. No. 4,333,979 to Sciaraffa et al. discloses a laminated fibrous web with differentially bonded layers as well as the method and apparatus for making such materials. The process provides a lightweight nonwoven web formed from continuous thermoplastic filaments substantially randomly oriented and pattern bonded, but further embossed under heat and pressure conditions resulting in an increased effective thickness providing softness and bulk while retaining other desirable physical properties such as strength. The bond pattern is composed of closely spaced point fused areas, while the subsequently applied embossing pattern comprises a gross pattern of much larger overall embossments.
U.S. Pat. No. 4,761,322 to Raley discloses a laminated fibrous web of differentially bonded layers as well as the method and apparatus for making such a web. The web is formed by the steps of forming a first fibrous layer of a first relatively higher density and bonding the fibers of the first fibrous layer to one another at a first relatively higher extent of bonding. A second fibrous layer is formed at a second relatively lower density and the fibers in the second fibrous layer are bonded to one another at a second relatively lower extent of bonding. Next, the first and second fibrous layers are bonded to each other at a third relatively lower extent as compared to the bonding of fibers to one another in the first fibrous layer.
U.S. Pat. No. 6,739,024 to Wagner discloses a method and device for producing a structured, voluminous nonwoven web or film. The web is produced by forming an unstructured web and subsequently processing this web using a pair of rollers. The pair of rollers consists of a positive roller having numerous positive bodies distributed over the roll sleeve surface and a negative roller having equally as numerous cavities. During the rolling process, the positive bodies engage with the cavities and stretch the unstructured web in the area of the roller engagements in such a way that a deep-drawn web structure with numerous cavities is produced. After the web has passed through a roller gap, the deformed web, still bonded to the positive roller, is brought into contact with a perforating tool and perforated. U.S. Pat. No. 3,542,634 to Such et al., discloses an apertured, bonded and differentially embossed nonwoven fabric. Deformable sheets of textile fibrous material are reformed by passing them through rolls engraved in a pattern of lands and grooves in such a way that a repeating pattern of three degrees of compression are effected; high compression where a land has traversed a land; intermediate compression where a land has traversed a grooves; and little or no compression where a groove has traversed a groove. The areas affected by the three degrees of compression are discrete and spaced apart areas of rhomboidal shape. The high compression areas may be bonded, for example, by the presence of thermoplastic fibers which are fused during embossing, or the high compression areas may be in the form of actual apertures in the fabric.
While the foregoing are examples of attempts to provide materials with the desired fluid handling properties, there is still a need for improved materials in this regard. The present invention is directed to a three-dimensional sheet material which can be used in this regard in conjunction with personal care absorbent articles including, but not limited to, diapers, training pants, incontinence garments, feminine hygiene products such as sanitary napkins and panty liners as well as other absorbent products including bandages and wound dressings.